01 Manual Discharge 01

Discharging1- 2002/10 (Ver.1)

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Preparations before entering port and discharging cargo Preparatory procedures before entering port and discharging cargo

Preparations before entering port and discharging cargo are to be made according to the procedures given below.

1. Checks, studies and investigations before entering port (P.1-2 to P.1-4)

Before entering port, thoroughly implement the checks, studies and investigations mentioned below, and study the items carefully to ensure safety during cargo operations. 1) Studies and checks related to the berth/terminal 2) Draft checks 3) Investigating the discharging and ballasting plans 4) Investigating the crude oil washing plan

2. Formulating plans (P. 1-5 to P1-13)

Formulate the plans given below after carefully considering the results of studies, checks and investigations of the discharging site. 1) Discharging plan (P 1-5 to P1-8) 2) Ballasting plan (P 1-9 to P1-10) 3) Crude oil washing plan (P 1-11 to P1-13)

3. Shipboard meetings (P1-14)

After formulating the plans, hold shipboard meetings on preparations for entering port and discharging cargo and on cargo operations.

4. Preparations for entering port and discharging cargo (P1-15 to P1-18)

Make preparations for entering port and discharging cargo in accordance with the decisions taken at the shipboard meetings.

5. Reports (P 1-19)

Submit the essential documents to the relevant departments after the plans have been formulated and the preparations for entering port and discharging cargo have been made.

6. Work before and after entering port (P1-20 to 1-25)

Perform the work given below after considering the timings before and after entering port.

1) Tank pressure controls 2) Ullage measurements 3) Preparations for starting IGS and scrubber pump

Chapter 1


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1. Checks, studies and investigations before entering port 1.1 General

Before entering port, thoroughly perform the checks, studies and investigations mentioned below to ensure safety during cargo operations.

1) Studies and checks related to the berth/terminal 2) Draft checks 3) Investigating the discharging and ballasting plans 4) Investigating the crude oil washing plan

1.2 Studies and checks related to the berth/terminal

Study and check the items below related to the berth/terminal and the waters in the vicinity. Refer to berth information published by the Tanker Association during the studies and checks. In case of doubtful items, confirm and clear the doubts with the terminal.

Click here to view video 001.mp4

1.2.1 Items related to entering port

1) Depth of water (berth, channel) 2) Maximum permissible draft and trim restrictions 3) Maximum permissible deadweight capacity or displacement tonnage 4) Maximum air draft 5) Maximum dimensions (length overall, breadth overall, depth) 6) Berthing side 7) Tide and current restrictions 8) Specific gravity of sea water

1.2.2 Items related to mooring

1) Number, position and strength of mooring dolphins 2) Location and arrangement of shore radars and existence of traffic separation systems at the terminal 3) Whether tugs and line handling boats required for maneuvering and mooring the ship can be used 4) Lines used on the tug (ship's lines or tug's lines) 5) Parallel body length forward and aft of the mid-point of the manifold at the predicted waterline in

the arrival/departure condition 6) Mooring equipment required (bitts for additional mooring lines, winches, etc.) 7) Side going alongside to ?


1.2.3 Items related to cargo operations

1) Number and size of hose connections and manifolds 2) Maximum reception flow rate 3) Manifold pressure limits 4) Allowable range of movement of Chiksan arm 5) Distance from the bow to the midpoint of the manifold 6) Ullage check 7) Ballasting and de-ballasting limitations 8) Crude oil washing guidelines of terminal (washing start period, number of tanks that can be washed,

whether tanks with different grades of oil can be washed, whether tanks with specific oil grades cannot be washed, whether fresh oil is required and its quantity, etc.)

9) Items related to tank pressure adjustments


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10) Whether means for line circulation available 11) Whether shore line flushing is required 12) Max Height of Manifold allowed from waterline

1.2.4 Exchange of information with terminal

Information necessary for cargo operations and information related to terminal regulations should be exchanged between the ship and the terminal using FAX, TELEX, e-mail or other means. Particularly, if STS cargo transfer operations are anticipated, communications, work conditions, berthing methods, preparatory work, transfer operations should be confirmed beforehand with the other ship.


1.3. Draft checks

1) Anticipated drafts when entering/leaving port (considering trim, heel, hogging/sagging and specific gravity of sea water)

2) Air draft from minimum predicted draft during the discharging operation considering tides (height from the surface of sea water to center of the diameter of the connection manifold )

3) Available under keel clearance

1.4. Investigating the discharging and ballasting plans The points below are to be considered when investigating the discharging and ballasting plans:

1.4.1 Efficiency of discharge

Formulate discharging and ballasting plans such that the efficiency of discharge of the cargo pump becomes maximum and the stripping time becomes minimum. Take into account the reduction in discharging time and quick dispatch of the ship.

For overall safety of tankers/terminals, please refer to the International Safety Guide for Oil Tankers and Terminals (ISGOTT), which is a useful reference.

1.4.2 Trim, heel and intact stability other attitude controls To maintain the trim, heel and other aspects that affect the ship's hydrostatic attitude so that rational ballasting work and maximum stripping effects can be obtained during cargo operations, the following points should be carefully considered: 1) Hull strength (BM/SF/FL longitudinal bulkheads) should be confirmed to be within the allowable

range of values. 2) The ship's attitude (trim, heel, etc.) should be within the range of limits stipulated by the terminal

. Forward draft . Forward draft in case of mooring at SPM . Air draft . Trim

3) Heel to port, heel to starboard or upright position should be adjusted at the bell mouth position. 4) Fenders may be damaged if the ship heels excessively during the discharging operation at the pier 5) Care should be taken against strong winds by referring to the latest weather information. Also, the

area of the hull exposed to the wind and the wind pressure should be carefully studied. (To be aware of traffic condition in the port /terminal passing the vessel which can affect vessels mooring & movement.)

1.5 Investigation of crude oil washing plan*1 Click here to view video 006.mp4

The aim of crude oil washing is to minimize residual oil and sludge as far as possible and to maximize discharge. Plans should be formulated to perform crude oil washing of as many tanks as possible if


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there is time before the ship leaves port and provided the permission of the charterer and the terminal can be obtained. If the time of entry into port and the schedule of the receiving side have not been finalized, plans should be made to wash the maximum number of tanks possible, study the timings for entry/departure into/from port and amend the plans as necessary. Where possible, additional ballast tanks *2 should be included in the tanks to be washed. Restrictions for crude oil washing include restrictions on oil grades used for crude oil washing and the washing of tanks with different grades of oil. These restrictions may be specified by charterer/terminal. However, if no clear-cut instructions are given, the permission of the charterer should be obtained before the submission of the plans (see "7. Reports" on P1-19 of the "Discharging Section").

*1 What is crude oil washing?

Crude oil washing refers to using a part of the cargo oil during discharging, and injecting this oil at a high pressure of 0.8 to 1.0 MPa (approximately 8 to 10 kg/cm2) into the cargo tank with a tank cleaning machine so as to remove as much of the sludge sticking to or deposited on the structures or on the bottom of the tank making use of the solubility action of crude oil. The ultimate aim of the system is to discharge cargo oil (crude oil) together with sludge and other deposits from the cargo tanks to shore tanks. The washing pressure and minimum trim mentioned in the Crude Oil Washing Operations and Equipment Manual should be strictly adhered to when performing crude oil washing. During the crude oil washing, the trim should be made as large as possible within the scope of limitations for the ship and the terminal so as to enhance the washing effect.

*2 What is an additional ballast tank? When very severe weather is anticipated, ballast water is filled in the cargo tanks. Such tanks are called additional ballast tanks. Tanks in SBT ships called Gale Ballast Tanks and Heavy Ballast Tanks are additional ballast tanks. Ballast water cannot be filled in tanks that have not been subjected to crude oil washing. The definition of additional ballast tank is given in the Crude Oil Washing Operations and Equipment Manual supplied by the shipbuilder.


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2. Discharging plan Click here to view video 004.mp4 2.1 General principles

1) The discharging plan is to be formulated based on the charterer's instructions. The plan should be formulated in accordance with the Operation Guidelines issued by the charterer and the various regulations of the terminal. The loading plan is generally formulated considering the discharging operation. However, since the loading of different grades of oil is common these days, the focus is on ensuring maximum cargo load. Consequently, smooth discharge according to the specified discharge sequence may not be possible, but the discharging plan should be formulated giving priority to ensuring safety of the ship and the terminal. Generally, the sequence for discharging cargo is specified by the charterer. In rare cases, the discharging may need to be performed according to the ship's discharging plan. In such cases, the plan should be established focusing on the hull strength, appropriate trim, efficiency of discharge, ballasting efficiency and COW.

In practice, discharging the cargo according to the specified sequence is almost never implemented. However, to minimize contamination of lines when handling high quality oil, the method of "LOADING THE BEST PRODUCT FIRST AND DISCHARGING IT LAST" may be adopted.

2) The discharging mode may be different and varied. Sometimes all the cargo may have to be discharged at one port or at two or three ports (multiple port discharging), or as in the case of the Kiire terminal, a part of the cargo may have to be discharged then the empty tank loaded, and furthermore, all the cargo may have to be discharged at the second port, or two or more kinds of cargo oil may have to be simultaneously discharged. Thus, the discharging mode may be extremely complicated. With improvement in the reliability of equipment installed in tankers, cargo discharging and loading operations are likely to become more complicated henceforth.

2.2. Discharge rate and discharge time

The maximum discharge rate for each grade of oil should be determined from the equipment on board the ship and the cargo loading condition, based on the results of studies of the discharging terminal. Furthermore, the average discharge rate for each grade of oil including the stripping time should be calculated.

The properties of oil affect the discharging time considerably. For further details, refer to the Table of Properties of Oil published by the Japanese Tanker Association, which is a useful reference.

2.2.1. Items to be considered Consider the items mentioned below when deciding the discharge rate and the loading time.

1) Number of manifolds used, flow rate restrictions, manifold pressure limits, etc. 2) Estimation of changeover time at the terminal and the ship for each grade of oil 3) Number of tanks to be discharged and number of ship's lines to be used for each grade of oil 4) Selection of pumps to be used 5) Relationship with time required for ballasting 6) Final stripping time and time required until completion of discharge operation including time for

checking dryness of tanks, lines and pumps 7) Grade of cargo oil 8) Discharging plan of terminal 9) Past records

2.2.2. Examples of general calculations

1) Deciding the maximum discharge rate Decide the maximum discharge rate taking care to adhere to the maximum allowable discharge rate

specified in the Instruction Manual supplied by the shipbuilder and retained on board the ship. The


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maximum discharge rate and maximum loading rate may vary according to the shipbuilder. The reason for the variation in the rates should be confirmed with the shipbuilder beforehand.

2) Allowable flow rate in pipe for butterfly valve a) Fluid flow rate: 6 m/sec.

Calculation example: Assume a 500-mm butterfly valve. r2 x 6m x 3,600sec. 3.14 x 0.25 x 0.25 x 6 x 3,600 = 4,239 m3/h

b) Gas flow rate: 36 m/sec. (flow rate limit due to flame arrester). Calculation example: Assume a 400-mm butterfly valve.

r2 x 36m x 3,600sec. 3.14 x 0.2 x 0.2 x 36 x 3,600 16,277 m3/h For loading, the vaporized crude oil content should be taken as 25% (36 m/sec. / 1.25 = 28.8 m/sec.). The gas flow rate is taken as 28 m/sec. considering its relationship with the loading rate.

3) Estimation of maximum flow rate accepted by terminal and discharging time for each grade of oil The discharging time for each grade of oil is estimated by taking 80% of the maximum flow rate accepted by the terminal as the average flow rate. Calculation example: Volume to be discharged .. 60,000 m3

Maximum flow rate accepted by terminal 10,000 m3/h Maximum discharging capacity of ship . 15,000 m3/h

10,000 m3/h x 0.8 = 8,000 m3/h 60,000 m3 8,000 m3/h = 7.5 hrs.

4) Estimation of final stripping time Assuming that the tank is stripped at least three times each stage, the time required is estimated as below.

a) Time required for checking dryness of tank: 30 minutes to 1 hour b) Stripping of lines, pumps and small-diameter pipes: 1 hour

c) Time for discharging drive oil in slop tank used for eductor: 1 hour d) Final stripping by stripping pump: 30 minutes

Total stripping time: About 3 to 3.5 hours Although plans are formulated assuming that crude oil washing does not affect the discharging time,

if additional time is required by the terminal or for cargo handling operations before entering the dock, then separate investigations are to be carried out as necessary.

5) Simple estimation of total discharging time The total discharging time is estimated by adding the discharging time for each grade of oil, the oil grade changeover time, crude oil washing time after temporarily suspending discharging operation and the stripping time. However, a simple method is to estimate the total discharging time by assuming the discharge rate as 70% to 75% of the maximum receivable flow rate of the terminal. This estimation, however, excludes the time for crude oil washing, which is implemented after suspending the discharging operation. If the number of oil grades is about 5, then discharging can be completed within the range of the times mentioned above. Calculation example: Conditions Volume to be discharged at the port: 300,000 m3 Maximum flow rate accepted at terminal: 10,000 m3/h Maximum discharging capacity of the ship: 15,000 m3/h

* Calculated Time required when the discharging rate is 75% of the maximum receivable flow rate at the terminal

300,000 m3 7,500 m3/h = 40 hrs. Time required when the discharging rate is 70% of the maximum receivable flow rate at the terminal

300,000 m3 7,000 m3/h 42.85 hrs.

2.2.3 Precautions During multiple port discharging (discharging at two or three ports), the various conditions may differ, therefore independent investigations are necessary. Records of discharging operations at various ports


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in the past serve as useful references, but for multiple port discharging, it is customary to estimate the maximum discharge volume for a specific draft since many of the terminals have their own draft limitations. In such cases, plans should be formulated in principle considering the ballast volume as zero and shifting the cargo bearing in mind that the normal practice is to control the ship's hydrostatic attitude.

* About cargo shift during the discharging operation

To retain the hull strength and the ship's hydrostatic attitude, simultaneous shift operations of two or more grades of oil should not be performed even if shifts of different oil grades become necessary during the discharging operation so as to prevent contamination of the oils. Rather than risk of contamination of oil by aiming to curtail the cargo handling time, it is preferable prolong this time a little, suspend the cargo handling operation temporarily and shift the cargo one grade at a time without contaminating it. It is also recommended at the loading/discharging plan preparation stage itself, the plan be formulated such that simultaneous shift of two or more different grades of oil does not occur. However, such a simultaneous shift of two or more different grades of oil may be implemented by preparing line drawings beforehand for the cargo shifts and carefully confirming the open/closed status of valves provided that a severe problem in the ship's hydrostatic attitude and hull strength is likely to occur if such a shift is not performed and provided that permission from the berth master is obtained. Additionally, not only should ullage measurements be performed but also the volumes of both cargoes to be shifted should be calculated and checks should be made to confirm that the cargo being shifted is not being discharged.

2.3. Selection of pumps to be used

The points given below are to be considered when selecting the pumps to be used.

2.3.1. Grouping of tanks VLCCs are generally constructed such that three grades of oil can be segregated and loaded into tanks. Three cargo main lines are directly connected to separate cargo pumps. Lines connected to the cargo pumps are called the No. 1 line, the No. 2 line and the No. 3 line respectively. Although cargo pumps are installed such that each cargo pump can discharge cargo oil through any of the lines, the general practice is to select the pump directly connected to each line provided there are no specific restrictions for doing so.

2.3.2. Natural segregation and complete segregation

1) Natural segregation Cargo oil is loaded into separate tanks, but mixing of cargo lines and pumps is permitted. 2) Complete segregation

Cargo oil is loaded by complete segregation including segregation of cargo lines and pumps using two valves. (Cargo oil is loaded through separate lines and the loadable quantity depends on the hull structure.) In rare cases, segregation of vapors may also be demanded. Washing of tanks to be loaded is generally required when complete segregation is adopted. In such cases, the washing water also needs to be segregated. In many cases, the free flow lines between the port and starboard slop tanks are segregated by only one valve. Care is necessary in such cases because if different grades of oil are loaded in the port and starboard slop tanks, complete segregation will not be possible.

2.3.3 Number of pumps

The resistance of pipes from the ship's tanks to the cargo pump and from the cargo pump to the shore reception tanks should be considered when deciding the number of pumps to be used. The relationship between pipe diameter and route loss due to resistance is "loss due to resistance is inversely proportional to the fifth power of pipe diameter." The relationship between flow rate and resistance is "for the same pipe diameter, the resistance is proportional to the second power of flow rate and the length of the pipe." The efficiency of discharge will reduce drastically if the pipe diameter and pipe length are not factored in the pump operation.


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Example: Maximum receivable flow rate at the terminal: 10,000 m3/h Capacity of ship's pump: 5,000 m3/h/unit

If the pumping arrangement is changed over from using one pump of 5,000 m3/h capacity to two pumps operating in parallel, the pipe route resistance increases due to the increase in the flow rate of oil delivered provided there is no change in the route on the discharge side. Larger discharge pressures are required of the pumps and the total flow rate will not reach 10,000 m3/h (twice the flow rate) anticipated by parallel operation. In this case, three pumps should be operated in parallel to achieve the required flow rate. If the example mentioned above is to be put into practice, then the number of pumps should be decided considering 70% to 80% of the actual pump capacity when discharging cargo below the maximum discharge capacity of the ship. Based on the above, the number of pumps to be used may be taken as three for a discharge rate of 7,000 m3/h.


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3. Ballasting plan 3.1 Importance of ballasting work

To account for strong winds due to changes in weather, a large draft should be maintained as far as practicable during ballasting work. This is important because the area of the ship exposed to the wind increases when the ship is in the empty condition at the completion of the discharging operation. Consequently, plans for ballasting work should be formulated after considering a proper balance between large draft and draft restrictions at the loading terminal. Ballasting is essential for controlling the ship's hydrostatic attitude (trim and heel) and the hull strength. Similar to the discharging operation, ballasting is an important operation.

3.2 Precautions 3.2.1 Precautions when formulating the ballasting plan

Depending on the terminal, the discharge of ballast water from APT (After Peak Tank) may be prohibited sometimes even if the APT is not connected to any cargo compartment, regardless of whether the ship is an SBT (Segregated Ballast Tank) ship, a double-hull ship or a single-hull ship. At the said terminal, if ballast water is filled in the APT for adjusting the condition of the ship during the discharging operation, it may not be possible to discharge the ballast water in the APT by the time the ship has to leave port. Even at terminals with no de-ballasting restrictions, it is important to formulate a ballasting plan wherein de-ballasting is avoided as far as practicable to prevent irregularities such as discharge of oil within the port area or damage to the oil fence due to discharge flows.

3.2.2 Precautions related to operation

Damage to the ballast tank or the ballast line may occur due to leaks during ballasting work in SBT ships. Again, in many single-hull ships, the ballast line penetrates cargo tanks, therefore, extreme care should be taken to prevent pollution of the sea by the oil. The precautions given below should be adopted before ballasting/de-ballasting.

1) Check for the presence of gas in the ballast tanks and confirm the absence of abnormalities such as

oil leaks by visual inspection and by using cotton waste. (This check should also be performed before the ship enters port in order to prevent problems after the ship enters port.)

Gas detection systems are provided in the ballast tanks of double-hull ships. During loading voyages, gas is monitored round the clock and safety is enhanced considerably. In spite of the above, the precautions and check items before ballasting/de-ballasting are the same as for a single-hull ship.

2) Before commencing the ballasting operation, be sure to open the valves in the empty tank and open the ballast line to the atmosphere, thereby preventing the water hammer *3 effect due to negative pressure. The main cause of the negative pressure in the ballast line is the negative pressure that remains in the piping after stripping tanks using eductors at the loading site as a result of a drop in the air temperature and sea water temperature.

3) Before opening the sea chest, station a watch in the vicinity of the sea chest to monitor it so that immediate measures can be adopted in the event of an unanticipated oil leak.

4) Apply pressure in the ballast line and monitor the suction pressure of the ballast pump. This will enable you to check for abnormalities such as pipe ruptures.

The method of performing checks differs depending on the condition of the cargo tanks and ballast tanks mentioned below. Check for abnormality in the suction pressure of the ballast pump during the hydrostatic test. Since some time is required for monitoring the pressure in the ballast line, perform the tests mentioned below beforehand.

a) Hydrostatic test when the cargo tank is full/ballast tank is empty If the ballast line passing through the cargo tanks is damaged, the valve in the empty tank can be opened before starting the ballasting operation so that the empty tank can receive the oily water. Abnormalities can be checked by gas inspections, visual inspections or by using cotton waste. During the hydrostatic test of the sea chest, if the line pressure rises, the abnormality may be in the tank penetration part; if the line pressure drops, the abnormality may be in the line to the empty tank or in


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the valve. b) Hydrostatic test when the cargo tank is half filled or empty/ballast tank is partially filled or half

filled If pressure is applied from a ballast tank with a level higher than that in the cargo tank and the line pressure drops, then the abnormality is likely to be in the ballast line.

*3 What is water hammer? If a liquid is filled in a space with high vacuum, the liquid moves vigorously and causes a momentary surge pressure. This momentary surge pressure is called water hammer. This surge pressure can damage the pipe, valve or the pump.

3.2.3 Precautions for drafts during voyages Operating conditions, such as drafts, that need to be strictly adhered to during a ballast voyage are given in the operational information supplied by shipbuilders. The Master and officers of the ship should familiarize themselves with these operating conditions. Such items should be indicated near the draft gauges on the front panel of the cargo console, together with indication of drafts corresponding to % propeller immersion to enable the conditions to be viewed at a glance.

Example: Takasago Maru 1)BALLAST CONDITION Aft draft : To ensure 55% (10.57 m) or greater propeller immersion 2) ROUGH SEA Forward draft: To be 7.8 m or greater Aft draft: To ensure 61% (11.14 m) or greater propeller immersion.


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4. Crude oil washing plan Click here to view video 006.mp4

MARPOL stipulates requirements related to crude oil washing. However, the ship has on board the Crude Oil Washing Operations and Equipment Manual, which is approved by the classification society. Thus, the crude oil washing plan should be formulated after becoming thoroughly familiar with the contents of this manual.

4.1 Advantages and disadvantages of crude oil washing 4.1.1. Advantages

1) Additional cargo can be loaded since residues in the tank have been reduced 2) Quality degradation due to mixing of different grades of oil is prevented 3) Pollution of the sea due to oil is prevented 4) Corrosion and rusting of tank is prevented 5) Tank cleaning work is reduced and working time is curtailed when the ship is in dry-dock 6) When internal inspection of tank is to be performed after the ship leaves port, the tank can be

cleaned to an extent that no sea water washing is necessary.

4.1.2. Disadvantages

1) Increase in the concentration of work together with parallel discharging/ballasting/crude oil washing operations

Crude oil washing methods can be broadly divided into the multi-step method (refer to "2.1 Types of COW methods" on P4-4 of the "Discharging Section.") , wherein the top part and the bottom part are washed in steps, and the single-step method wherein the entire internal surface of the tank is washed. Crude oil washing should be implemented whenever possible for controlling sludge, in addition to charterer's requirements, but the risk of increasing the work concentration cannot be totally avoided. Double-hull ships have simple tank construction therefore, the washing effect is adequate even if the single-step washing method is adopted. However, the washing method should be selected considering the construction of the ship, properties of washing oil, number of machines available and their characteristics and the cargo handling conditions and the risk should be mitigated. 2) May affect the discharging time and may increase the cargo handling time. 3) Vapor losses occur

4.2 Items to be considered

The items to be considered when formulating the cargo washing plan are given below.

4.2.1 Limit of usage of the same washing oil

1) If the same washing oil is used for washing several tanks, the solubility effect of the crude oil will deteriorate.

Provided tank conditions are not special, past records of internal inspection of tanks confirm that up to 5 tanks of a double-hull ship can be washed with the same oil without any problems in particular.

2) The minimum stripping capacity is taken as 1.25 times the total discharge capacity of all washing machines working simultaneously in the bottom washing stage.

4.2.2 Sludge control

1) About one fourth of all tanks other than ballast tanks when leaving port, ballast tanks when entering port (CBT (clean ballast tanks)) and additional ballast-filled tanks should be subjected to crude oil washing for controlling sludge. Additional ballast tanks may be included in these additional (one-fourth of the tanks).


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2) Ballast water should not be filled in tanks that have not been subjected to crude oil washing. Ballast water filled in tanks in which crude oil washing has been performed but sea water washing has not been performed should be treated as dirty ballast water.

3) Crude oil washing of the same tank need not be carried out more than twice in four months. This does not mean that each cargo tank should be washed once in four months. 4) Crude oil washing should not be performed during the ballast voyage, that is, during the voyage

between the final port of discharge and the port of loading. 5) All crude oil washings should be completed before the ship leaves the final port of discharge. 6) Crude oil washing can be performed while the ship is underway between several ports of discharge.

In this case, the washing should be performed after obtaining the charterer's permission beforehand.

4.3 Precautions when implementing the plan

The precautions mentioned below are to be taken when implementing the crude oil washing plan.

1)To prevent generating excessive static electricity during the washing due to moisture in the washing oil, the washing oil supply tank should be filled at least to a level greater than 1.0 m before using the oil.

2) Wet oil that has been loaded on top (LOT) should not be used for crude oil washing. If such a loaded tank is to be used as the crude oil supply tank, it should be fully discharged, and then crude oil containing no moisture/water should be shifted to this tank before starting crude oil washing. This crude oil is called dry oil.

3) The tank pressure is to be maintained above 2 kPa (about 200 mmAq) during the crude oil washing. However, measures should be taken to ensure that this pressure does not exceed 10 kPa (about 1,000 mmAq) accounting for pressure setting errors in the breather valve.

4) The implementation of crude oil washing after stopping the discharge of high vapor pressure cargo should be confirmed before starting the cargo handling operation.

5) The trim during the washing of the bottom part of the tank and during stripping should be in accordance with the Crude Oil Washing Operations and Equipment Manual of each ship. The required value is generally 4 m or above.

6) The oxygen concentration should be measured 1 m below the deck and at the center of the ullage space before the crude oil washing of each tank. At each of the measured positions, the oxygen concentration should not exceed 8 vol%.

7) Restrictions for crude oil washing include restrictions on oil grades used for crude oil washing and the washing of tanks with different grades of oil. Charterers/terminals sometimes specify these restrictions but the charterer's permission should be obtained before submitting the plans where no specific instructions have been given.

* About high vapor pressure cargo Means should be available to handle high vapor pressure cargo with Reid vapor pressure greater than 0.03 MPa (4.5 psi). Cargo with Reid vapor pressure greater than 0.05 MPa (7 psi) is highly volatile and vapor losses are high. If crude oil washing is carried out after suspending the discharging operation, the tank pressure rises and in the worst case scenario, gases may be unavoidably released to the atmosphere as tank pressure control becomes disabled. However, sometimes only bottom washing is permitted as in the case of UPPER ZAKUM and QATAR MARINE. In any case, the terminal restrictions should be confirmed beforehand.

True vapor pressure (same definition as saturated vapor pressure) should be mentioned when talking about high vapor pressure cargo. Although the true vapor pressure of oil mixtures is a good indicator of gas generating ability, its measurement is extremely difficult. Consequently, the Reid vapor pressure is referred to here since its measurement is practical.


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Examples of high vapor pressures are given below.( 1 PSI = 0.07031 kg/cm2 = 0.0069 MPa )

CRUDE OIL R.V.P (PSI) CRUDE OIL R.V.P (PSI) Brass light 12.7 Qatar land 8.0 to 11.2

Oseberg 7.1 to 11.0 Upper zakum 7.0 to 10.3

Khafji 6.4 to 6.8 Qatar marine 5.8 to 7.1

The maximum vapor pressure at constant temperature is called the true vapor pressure. It is used as a scale for distinguishing whether the liquid will vaporize or not. The Reid vapor pressure expresses the pressure in a sealed space filled with vapor at 100F. Thus, when the temperature rises above 100F, the vapor pressure increases further and if the temperature drops below 100G, the vapor pressure also drops.

4.4 Criteria for stopping crude oil washing When all cargo operations (cargo discharging, COW, tank washing, etc.) other than cargo loading operation have reached the criteria mentioned below, then crude oil washing should be stopped. However, if the charterer or the terminal has specified restrictions on oxygen concentration that are stricter than the criteria given below, then those restrictions take priority.

1) If the oxygen concentration in the tank exceeds 8% (volumetric ratio) 2) If supply is no longer possible because of failure of the inert gas system 3) If the pressure within the tank has dropped below +1.961 kPa (+200 mmAq)


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5. Shipboard meetings Click here to view video 007.mp4

Shipboard meetings are held for ensuring safety. After formulating plans and approving them, the meetings are held to familiarize the crew members with preparatory work before entering port and before discharging cargo, and with discharging procedures. The following should be implemented when holding a shipboard meeting:

1) The Master should check cargo handling plans and the discharging plan prepared by the Chief Officer and give the necessary advice before the meetings for discussing cargo handling operations.

2) The Chief Officer should hold shipboard meetings for discussing cargo handling operations and notify the Chief Engineer and all deck ratings the discharging plan and cargo handling procedures before the ship enters port.

3) The Chief Engineer should give the necessary advice on cargo handling work to the Chief Officer. 4) The Chief Officer should notify the officer of the watch the valve operating procedures for special

discharge work such as commingled loading *4, mixed loading *5, load on top *6 and shore line flushing *7.

*4 What is commingled loading?

"Mingling" refers to the mixing of two or more elements such that they can be distinguished. When this word is combined with "Co" (meaning together, common, mutual, equivalent), the meaning of "Commingled" becomes "mixed." With the understanding of the charterer, two or more different kinds of cargo may be mixed at the mixing ratio without special instructions. Such mixing is performed for achieving the maximum loading capacity. All cargoes cannot be commingled; only cargoes for which permission for mixing have been received from the charterer should be mixed.

*5 What is mixed loading?

Mixed loading is used when the final result of mixing is a practically uniform product of all elements in the mixture. Thus, the mixing ratio needs to be specified. For instance, if Oman Strait Run Residue (1st Loading) and Oman Export Blend (2nd Loading) are to be loaded in the same tank after establishing the mixing ratio at Mina al Fahal, the two grades of oil are considered to subscribe to "mixed loading." Blend refers to the mixing of different grades of oil to obtain a dilute mixture.

*6 What is Load on Top (LOT)? Refers to the method of loading cargo oil in oily water storage tanks after discharging the sea water recovered after the shore line flushing, or after discharging oily water generated after sea water washing during repairs/inspections of cargo tanks. Tanks that are used to store this oily water (dirty water) are called slop tanks.

*7 What is shore line flushing?

Sometimes submarine lines of a terminal such as SPM need to be flushed with sea water (sea water replacement) during periodic inspections or repairs/surveys. In such cases, sea water is pumped into the submarine lines at constant pressure and constant flow rate to flush the lines and replace the liquid in the lines, using the tanker's pumps. Such an operation is called "shore line flushing."


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6. Preparatory work for entering port/discharging cargo 6.1 Additional explanations on check list

Preparations and inspections for entering port/discharging cargo are mainly according to the SMS check list.


1) Compound pressure gauge of manifold/gate valve Confirm that all the installed pressure gauges on the inboard side and outboard side of the gate valves on port and starboard sides are in a satisfactory condition. Open the cocks of the relevant pressure gauges. (During loading, open the pressure gauge cocks not only on the inboard side of the gate valve at the hose connection on the side or loading arm, but also on the outboard side and the opposite side.) If the pressure gauge is fitted or removed frequently, the threads of the gauge may be damaged resulting in oil leaks. Accordingly, the pressure gauge should always be retained in the fitted condition. 2) Specified values of IG main pressure and P/V breaker Fit pressure gauges in all cargo tanks. When fitting the gauges, compare the gauge values with the specified values of IG main pressure and P/V breaker value in the CCR/bridge and adjust if necessary. In case the IG main pressure can only be grasped as the typical pressure in each tank in the CCR. In such a case, it should be understood that the prerequisite is that the IG branch valve of each tank should be open. It should also be borne in mind that the IG branch valve may be closed due to mishandling, internal defect and inadequate checks (removal of blind after gas freeing operation or after dry-docking work can be overlooked), as a result of which the tank could be damaged. 3) Transceiver call test Call tests should be implemented for all communications equipment such as transceivers. Establishment of communications procedures especially in team work such as cargo handling work, is extremely important. 4) Lighting test Lighting tests of illumination equipment should be carried out and electric bulbs in pump rooms and other store rooms should be inspected. 5) Inspection of portable detectors

Click here to view video -009.mp4 Measuring equipment such as HC meter, O2 meter, H2S meter and simple O2/ H2S meter should be inspected and kept charged. Such detectors should always be kept in a condition such that they can be used immediately when required. HC meter, O2 meter and H2S meter should be provided at the entrance of the pump room so that safety within the room can be confirmed before entering the room. 6) Checking the operation of emergency hydraulic hand pump Preparations should be made and work checks carried out on the emergency hand pump in the pump room and manifold. However, in practice, the operational check of the hand pump is done during the actual voyage since its operation can be confirmed by actually operating the valve.

A valve whose operating condition can be easily understood (such as a direct filling valve) is ideal for training beginners in the handling of the emergency hand pump. Also, the locking mechanism can also be practically observed. Therefore, it is important to create opportunities and educate the staff in handling the emergency hand pump.

7) Prior investigation of scupper plugs


Prior investigation of scupper plugs is necessary because some discharging terminals have special rules for handling these plugs. For instance, there is a rule that scupper plugs should be sealed using cement or putty on top of the plugs because a scupper plug by itself is considered to have inadequate sealing ability. Precautions are also necessary in ships where plug sizes differ with the scupper and


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against damaged seals. 8) Preparations for equipment and tools to prevent oil pollution

Click here to view video 011.mp4 Equipment and tools to prevent oil pollution should be kept ready near the manifold. Among such equipment, the line proportioner (or pickup tube) requires permission for using it for treating oil. Training should be imparted to responsible personnel in handling such equipment whenever opportunity arises. Oil treatment equipment and tools are of various kinds. The usage methods of those equipment on board the ship should be confirmed. 9) Checking fire extinguishing equipment Depending on the shipyard, portable carbon dioxide extinguishers may be used on board the ship as fire extinguishing equipment with vent riser. These equipment should be checked. Portable carbon dioxide fire extinguishers should be kept ready with hose connections at all times so that they can be readily used during cargo handling operation if required. Vent fires actually occur during the loading operation. Therefore, training in fire extinction is very important. 10) Pressure tests of the cargo/crude oil washing lines

Click here to view video 095.mp4 Lines should be pressure tested at 110% the working pressure at appropriate periods (when a deficiency is detected, repaired and furthermore when a pressure test is to be carried out) especially when there is time before the ship enters port to confirm the absence of abnormalities and leaks in the equipment and lines. The working pressure of the cargo and crude oil washing lines should be checked beforehand. These values are given in the Crude Oil Washing Operations and Equipment Manual of the ship. At this stage, the correct operation of the emergency shut-off devices in addition to functional tests of cargo pumps, tank cleaning pumps and stripping pumps should be confirmed. Test results (date of implementation and pressure in case of tests of cargo lines and crude oil washing lines) should be displayed at easily visible locations on the pipelines.

Normally, the operating pressure mentioned in the Crude Oil Washing Manual is greater than 0.78 to 0.83 MPa (8 to 8.5 kg/cm2) (this value is necessary for reaching the surfaces of the COW tank walls). Therefore, assuming that the crude oil washing is implemented at 0.88 MPa (about 9 kg/cm2), then 0.88 x 1.1 = 0.97 MPa (9 kg/cm2 x 1.1 = 9.9 kg/cm2), and the test should be carried out at a pressure of 1.0 MPa (about 10 kg/cm2). The pressure tests of the cargo line should also be carried out at the same time as that of the COW line. In this case, the test is required to be performed at 110% of the operating pressure. After piping systems are installed on the ship, they are tested at 150% of the operating pressure.

6.2 Checking the open/closed position of valves Click here to view video 012.mp4

The points mentioned below should be considered when checking the open/closed positions of valves. (Refer to 4.1 Functional test of hydraulic valves" on P 4-15 of the Navigation Section.)

1) Confirmation of the closed/open positions of the valve is generally performed one day before the

ship enters port, although this period could be affected by the sea and weather conditions. 2) Valves may be categorized into hydraulic valves and manually-operated valves. The open/closed

positions of all the valves should be checked in accordance with the check list prepared by the ship. These positions should also be matched with the indications on the mimicked diagram in the CCR simultaneously. The open/closed positions of cargo tank valves should be checked from the designated values in the local box on the upper deck.

3) The check should not only be limited to the open/closed positions of valves, but should also include inspection of the level of the operating oil in hydraulic equipment and hydraulic piping.


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Consideration should be given to including items such as check of nitrogen charge pressure (once every six moths) of accumulator periodically and inspection of operating oil of hydraulic equipment (once a year: analysis by testing organization) in the check items.

4) Valves should be checked item by item properly, and orders/replies should be clearly given and received.

5) Checks should be made to ensure that measures against liquid sealing of oil or sea water have been thoroughly adopted.

6) Depending on the condition of the ship, the pump operator should generally be designated as the inspector and given the responsibility for checking the open/closed position of valves. The pump operator should always sign the check list after completing the inspection and obtain the approval signature of the Chief Officer.

7) The Chief Officer should check the IG branch valve himself, and at the same time should check the tank pressure and record it. The Chief Officer should retain the key for the lever setting pin of the valve and keep it in safe custody.

*8 What is liquid-sealed condition?


1) The condition in which oil or water is not completely removed from within a pipe and remains sealed in it is called liquid-sealed condition. If the liquid is allowed to remain as it is, it may expand within the pipe due to atmospheric effects such as direct sunlight or rise in air temperature, leading to excessive pressure within the pipe. It may also lead to defective valve operation, leaks from the flange of the pipe connection or from the Dresser coupling and cause damage to pipe and valve. The elimination of the liquid-sealed condition is called removal of sealed liquid.

Safety valves and pressure gauges that account for such a condition are not normally installed in the cargo lines of conventional tankers, therefore adequate precautions should be taken. 2) The sealed liquid condition may arise not only in cargo lines but also in ballast lines. Care is

necessary, especially in cold regions, because after discharging cargo, if the sea water temperature rises, the pressure within the ballast line rises steeply.

3) Fig. D-1-1 shows the values of rise in pressure within pipes corresponding to the rise in temperature in the liquid-sealed condition.

4) For details of measures to prevent the liquid-sealed condition, refer to "3. Valve positions after discharging cargo," P6-8 of the Discharging Section and "4. Setting valve positions for navigation," P5-7 of the Discharging Section.

6.3 Ensuring tanks for fresh oil


Some sea berths or terminals (Mizushima JOMO terminal, Kashima, etc.) require that fresh oil be used to replace oil (mixed with impurities such as sludge and rust) used for crude oil washing so as to prevent such oil from remaining in the submarine lines. In such cases, tanks for fresh oil should be kept ready beforehand. Precautions are necessary because when the final stripping of tanks that have been washed (COW) with eductors, the collection tank (normally slop tank) will not be treated as a fresh oil tank.

6.4 Anti- freezing measures

Anti-freezing measures given below should be adopted in cold regions depending on the season and area of operation of the ship. Anti-freezing measures are very important especially in cold regions. If these measures are neglected, pipes and valves may be damaged leading to major problems.

1) P/V breaker


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Adjust the seal water level, and fill in the appropriate amount according to the usage method of anti-freeze solution.

2) Deck water seal No anti-freezing measures are required for deck water seals since they contain heating devices that make use of steam. However, check the seal water level and if necessary, make adjustments.

3) AUS seal water tank Check the seal water level and if necessary, make adjustments. Fit the temperature gauge to the tank casing.

4) Slop tank heating line Open the drain valve and drain out the liquid that has accumulated in the line.

5) I.G. line Open the drain valve and drain out the liquid that has accumulated in the line.

Fig. D-1-1


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7. Reports 7.1 Reports to the charterer, agent's office and ship owner

After formulating plans and completing preparations before entering port and discharging cargo, submit the reports mentioned below to the charterer, agent's office and the ship owner.

1) Results of safety inspection before entering port Inspect and test items requested by charterer/terminal/agent's office and submit the report. The report should mainly contain measures to prevent pollution of the sea, measures to prevent air pollution, condition of pumps, existence of leaks from pipes related to cargo handling, condition of equipment such as valves, level gauges, hydraulic equipment, existence of abnormalities in deck machinery, mooring equipment and hull structures. 2) Discharging plan according to company-specified form 3) Prior notification of crude oil washing plan 4) Crude oil washing plan 5) Cargo plan

7.2 Reports to regional authorities

Prepare the documents mentioned below based on approved discharging and cargo oil washing plans submitted to the charterer, and send the same through routes predetermined by each ship.

1) Prior notification of crude oil washing plan 2) Crude oil washing plan

Once these documents are submitted, crude oil washing of tanks other than mentioned in the plans cannot be carried out. However, the number of tanks specified in the plans can be reduced if requested by the charterer or the terminal because of problems in the sailing time or other reasons provided the rules are strictly adhered to.


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8. Work before and after entering port Click here to view video 013.mp4

8.1 Tank pressure controls Except for some discharging terminals, release of gases during berthing is prohibited near most terminals. Therefore, tank pressures should be adjusted before entering port and before berthing at the terminal.

8.1.1 Tank pressure before entering port

The tank pressure may rise depending on the weather, and inevitably lead to release of gas to the atmosphere. To avoid such a condition, some terminals require that the tank pressure be reduced to about 2.0 kPa (approximately 200 mmAq) in waters where it is safe to release gases to the atmosphere before entering port.

8.1.2 Tank pressure control

Since the reserve capacity in the upper part of the tank is small in the loading condition, the tank pressure rises until the start of the discharging operation due to the rise in the temperature of outside air, and the pressure in the breather valve may sometimes rise to the operating pressure setting of 13.7 kPa (1,400 mmAq). When the pressure is anticipated to rise to this value by the time of commencement of discharging, efforts should be made to maintain the tank pressure below the pressure setting such as by spraying sea water on the deck and cooling it. The tank pressure varies depending on the season, the weather and the time of entry of the ship into port. It is well known that the weather at that time is particularly an important deciding factor.

8.1.3 Precautions

1) When the tank pressure reduces, ventilation should be regulated, the vent riser valve should be opened from a small value to 30% of the maximum opening level, and measures should be adopted to prevent dispersion of oil mist due to abrupt valve operations. Pressure surges *9 when closing the valve should also be avoided and the valve should be closed gradually from 30% to 20% to 10% to fully closed condition. When a pressure surge occurs, the breather valve of the centralized vent system activates. The breather valve and the P/V breaker are the safety valves of the tank. Care should be taken to ensure that these valves do not activate without a proper reason.

2) It should be borne in mind that offensive odors due to release of gases to the atmosphere are treated equivalent to pollutants that cause pollution of the sea due to oil at terminals near residential areas.

3) It should also be borne in mind that "pollution of the sea by oil," "offensive odors" and "low-frequency pollution" are the most important causes for concern during tanker operations.

*9 What is a pressure surge?

Refers to abrupt pressure variation in a piping system when an abrupt change occurs in the flow rate of liquid in the pipe. A pressure surge generally occurs as a result of one of the following during the tanker loading operation:

1) Closure of automatic shut-off valve 2) Abrupt closure of non-return shore-based valve 3) Abrupt closure of butterfly valve 4) Abrupt closure of motorized valve

8.2 Ullage measurement


Sometimes ullage measurements are required to be carried out before the ship enters port. In such cases, the following precautions should be taken to prevent accidents to deck workers due to gas inhalation.


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a) Workers should stand perpendicular to the direction of wind b) Closed methods such as MMC should be adopted as far as possible.

During measurement of loaded crude oil with large hydrogen sulfide content such as Qatar Land, appropriate respiratory protection apparatus should be used.

8.3 Preparations to start IGS and start timing of scrubber pump Click here to view video 015.mp4

The start timings of IGS and scrubber pump are very important for preventing cargo handling delays and marine pollution.

8.3.1 IGS applications

IGS (Inert Gas System) is installed with the aim of inerting the space within the tank. It supplies inert gas generated by combustion in the boiler to the reserve space in the cargo tank that occurs as discharging of cargo progresses. This action of the system prevents negative pressure in the tank. (The gas supply capacity is regulated at greater than 1.25 times the maximum discharge capacity). The scope of application of inert gas systems is extensive, with some of them being used as accessories to the fire extinguishing system.

8.3.2 Starting the scrubber pump

The scrubber pump forms part of the IGS. Its main functions are to wash and cool the combustion gases. Even if the scrubber is adequately washed, there is a possibility of discharge of soot overboard when the pump is started. To prevent such problems, it is essential to start the pump by standby for entering port. As far as possible, the pump should be started when an adequate margin of time is available (for instance before entering the Tokyo Bay, Ise Bay or the Bungo Channel).

8.3.3 Time of starting IGS and supplying inert gas Click here to view video 024.mp4

1) Communicate with the Engine Department before the preparations for equipment to be used and before using them. Maintain close contact with the department to ensure that no inconsistencies arise.

2) Keep the deck water seal pump running at all times passing water through it even if it is meant for exclusive use.

3) Operate the scrubber pump beforehand. 4) Before operating the cargo pump, open the boiler uptake valve, start the IG main fan to be used to

set the inert gases to be released to the atmosphere. 5) Confirm that the tank pressure setting is the same as the planned value. Pressure setting is generally about 6 kPa to 8 kPa (about 600 mmAq to 800 mmAq). However, when the ship is underway in the Pacific Ocean in winter, the pressure may be raised to 10 kPa (about 1000 mmAq) during the final stage of discharging before sailing. Conversely, the tank pressure in a tanker sailing south may be anticipated to rise; therefore, the pressure may be sometimes be adjusted to a value slightly below the average value. Thus, the pressure may be decided according to the ship's route. 6) Adjust the oxygen concentration of inert gas when the starting of the cargo pump is requested and

make preparations for supplying the gas to the tank. Confirm that the oxygen concentration of the inert gas to be supplied to the tank is less than 5 vol%.

7) When the cargo pump is ready to be used, push the IG supply button and start supply the inert gas to the tank. Never start the discharging operation before supplying inert gas to the tank. During automatic operation, the tank pressure is adjusted to the pressure setting.

8.3.4 Precautions

1) There have been some instances of problems in the past when the scrubber pump was operated after the berthing of the ship and soot was discharged near the sea surface to pollute the sea water. Care should be taken to prevent such an incident as claims may be made by the terminal. A similar


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phenomenon may occur if the pump operation is stopped temporarily and restarted. Thus, even if cargo handling is suspended for a long period, continuous operation of the pump is recommended.

2) Many tasks are carried out in parallel before the discharging operation. Also, the IGS control panel is installed athwart ship with respect to the cargo console. Therefore it is essential that various tasks be assigned correctly so that the supply of the inert gas is not overlooked. Putting up an indication such as "Start IGS?" on the front panel of the cargo console is one such measure to prevent overlooking the start of the IGS.

3) When the load variation of the boiler is large, the oxygen concentration may not remain steady. In such cases, black smoke is likely to be generated. Thus, care is necessary to prevent pollution. Measures to prevent such occurrences include avoiding abrupt pump operations and always communicating with the Engine Department before making pump adjustments.

At seasons when jellyfish are abundant in the waters, the strainer of the scrubber pump may become clogged by jellyfish and the pump operation may be disabled. In such a case, cargo handling will have to be suspended. It has been reported that such problems have been eliminated by spraying the vicinity of the sea chest with sea water using the fire extinguishing hose.


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9. Meeting before the start of discharging operation Click here to view video 016.mp4

The meeting before the start of the discharging operation is an important and essential meeting for performing the discharging operation safely and efficiently. At terminals where the ship has called earlier, relevant documents related to the terminal should be checked beforehand.

9.1 Persons present at the meeting

Personnel associated with cargo handling operations listed below should be present at the meeting before the discharging operation. The meeting should be held according to the meeting documents prepared by the terminal under the leadership of the berth master. The Master and the Chief Engineer should make efforts to be present at the meeting as far as possible even if their presence is not required.

1) Berth master 2) Personnel associated with the terminal 3) Chief Officer 4) Responsible superintendent of the ship 5) Port Captain

9.2 Check items 9.2.1 Items related to safety

1) Locations designated for smoking 2) Restrictions on galley fires and cooking appliances 3) Criteria for stopping or suspending cargo handling operation 4) Information related to safety regulations and pollution prevention regulations of the port and the

terminal 5) Methods of obtaining assistance from the terminal in an emergency 6) Information related to activation of emergency shut-off devices 7) Communication methods and contents of the same between terminal and the ship 8) Maximum allowable discharge rate and maximum pressure 9) Information related to measurement, sampling, temperature and water measurements 10) Items related to cargo oil (temperature, specific gravity, moisture content, etc.) 11) Items related to replenishment of oil, water, ship's stores and provisions 12) Items related to ballasting/de-ballasting 13) Items related to crude oil washing 14) Repair work and inspection work 15) Whether berth master or terminal staff are present on board the ship

9.2.2 Items related to cargo operations

1) Number and size of manifolds used 2) Grade and quantity of oil to be loaded and tanks in which cargo is to be loaded 3) Whether water is mixed in cargo oil 4) Discharging sequence 5) Restrictions on flow rate received at the terminal 6) Manifold limiting pressure 7) Shore reception tanks 8) Method of changing over the grade of oil 9) Discharging time 10) Range of movement of Chiksan arm 11) Restrictions on the time of start of crude oil washing and whether measurement of oxygen

concentration in the tank is to be witnessed


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12) Handling of the Chiksan arm at the final stage of discharging (whether the number of Chiksan arms to be used is to be reduced)

13) Procedure for disposal of oil remaining in Chiksan arm or hose 14) Method of performing dry checks and tank pressure at that time

9.3 Documents to be submitted

1) B/L COPY 2) N/R 3) TIME SHEET 4) DRY CERTIFICATE 5) LETTER OF PROTEST 6) SAMPLE OIL 7) DISCHARGE CERTIFICATE *10 8) Report of ullage measurement by ship (loading area, Malacca Strait, at berthing)

*10 What is the DISCHARGE CERTIFICATE?

The DISCHARGE CERTIFICATE (refer to Fig. D-1-2) received by the ship at loading ports such as Qatar shows the evidence that the Customs at the loading site actually performed the discharging and requires this certificate to be returned.


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